The presence of a search service is important to searching for information desired by a user from among a vast amount of information present on a network. For example, to search for a Web page using the Internet, a user selects one service from among a plurality of search services, and then inputs a keyword as a search request to obtain his desired information. The search service performs information searching in response to the input keyword, and presents the search result to the user.
Information searched by the search service frequently becomes large in volume, and the user has difficulty finding the user's desired information from among the vast amount of information. Since the Web pages are currently more and more increasing, presenting a number of pieces of searched information in an easy-to-understand fashion to the user becomes a serious concern.
Methods of presenting the searched information organized in an easy-to-see fashion to the user are currently becoming commercially available. For example, researching is performed using a keyword obtained from the results that have been searched using the keyword input by the user. The user thus narrows down the search so that a Web page desired by the user becomes easy to find. Specifically, a keyword characteristic of a set of search results of the search is extracted to find a set of information really desired by the user.
Finding a set of pieces of information having a property of similarity from a vast amount of information is called a “clustering”. The clustering, which is a well-known technique in the information processing field, is widely used to categorize a large amount of documents.
It is not an accepted practice to subject search results, provided by search services (general-purpose search services) widely used by common users, to the clustering process. As already discussed, typically, information is extracted in response to the input keyword, and the extracted information is then simply presented to the user in a simple list. The user is thus forced to perform a troublesome job of finding the user's desired information from numerous listed pieces of information.
It is an object of the present invention to present searched information in an easy-to-see fashion to a user by clustering the search result provided by a general-purpose search service.